This application is a request for a Mentored Patient-Oriented Research Career Development Award (K23) that will enable Dr. LaFrance to continue to develop his programmatic line of research in the treatment of psychogenic nonepileptic seizures (NES). NES resemble epileptic seizures, but have no associated epileptiform activity with the behaviors. NES have no single cause and are associated with underlying psychological problems and co-morbid psychiatric diagnoses. Patients with NES are often difficult to manage, severely disabled and frequently encountered in neurology, psychiatry, and emergency departments. The disorder is not responsive to antiepileptic drugs (AEDs), and a number of patients with NES are inappropriately treated with aggressive and invasive measures. Dr. LaFrance's training goals are to: 1) Develop expertise in designing and executing clinical trials studying treatments for patients with NES. 2) Gain expertise in biostatistical analysis, for designing and evaluating clinical and interventional studies. 3) Develop skills with specific psychotherapies for integrating psychosocial treatments in NES research. 4) Gain additional expertise in the field of epilepsy, focusing on epilepsy monitoring techniques. These training goals will be achieved through a 5 year research program that utilizes 1) the resources available at the Brown Medical School, 2) the experienced mentorship provided by Drs. Ivan Miller, Gabor Keitner and Andrew Blum and the expertise of the assembled consultant team, 3) focused coursework and clinical experiences, and 4) the proposed clinical intervention research project. The proposed research extends the natural progression of Dr. LaFrance's current research in NES under his NIH/Brown Institutional T32 fellowship. The application builds on Dr. LaFrance's clinical training in neurology and psychiatry by providing research experience in grantsmanship, research design, and exposure to combined modality interventions. The Specific Aims of this application are 1) to investigate the efficacy of sertraline in treatment of psychogenic NES and its co-morbid psychiatric disorders and 2) to identify predictors of response to treatment and to identify potential mechanisms of NES.